#include<bits/stdc++.h>

#include

using namespace std;

int n,m;

queue q;

int main(){

cin>>n>>m;

for(int i=1;i<=n;i++){

	q.push(i);

}

while(q.size()>1){

	int i=m-1;

	while(i--){

		q.push(q.front());
  
		q.pop();
  
	}

	q.pop();

}

cout<<q.front();

return 0;

}